Field of the Invention
Aspects of the present invention relate generally to an electronic device and a method for sensing touch force and, more particularly, to an electronic device and a method for sensing touch force using a pressure sensor.
Description of the Related Art
Electronic devices such as cellular telephones are sometimes provided with pressure sensors. For example, a cellular telephone may be provided with a pressure sensor that is embedded in the cellular telephone. The pressure sensor may be used to measure the actual atmospheric pressure at the location of the cellular telephone, and estimate altitude for providing GPS route information.
However, in recent years, it is apparent that the altitude cannot be measured accurately using only a conventional pressure sensor because the altitude reading is susceptible to error caused by changes in temperature and barometric pressure.
Currently, touch display screens have become ubiquitous in current cellular telephones. Touch display screens eliminate the need for key pads. In one adaptation, the touch display screens are used, not only as a replacement for key pads, but as a user interface that detects user gestures on the touch display screen and translates the gestures into commands to be performed. However, the touch display screens are, conventionally, an LCD (liquid-crystal display) technology, or an LPD (light emitting polymer display) technology. The display screens are overlaid with a touch sensor, which use touch sensing technology such as capacitive, resistive, infrared, and surface acoustic wave technologies, to determine one or more points of contact with the touch display screens. The touch sensing technologies, however, receive information in two-dimensions in the plane of the display screen.
Therefore, how to apply the pressure sensor to detect three-dimensional touch information and to avoid changing the structure of an existing electronic device (e.g. a cellular telephone) has been an important subject in design of the cellular telephone.